The present invention is directed to a dispenser for cooling and dispensing liquids, and more particularly, a dispenser for cooling and dispensing liquids which can continue to dispense liquids even when the liquid in the cooling reservoir is frozen.
In order to store and cool liquids for consumption, such as water, it is known to provide a cooling reservoir for storing the water, and to connect a spigot to the cooling reservoir for dispensing the water. A thermoelectric device may be used to cool the water before it is dispensed. For example, U.S. Pat. No. 5,544,489 to Moren discloses an apparatus for dispensing a cooled liquid which utilizes a thermoelectric device. The apparatus disclosed in that patent includes a compartment having a wall for retaining the water to be cooled and dispensed. A thermoelectric device having a first surface with a relatively cool temperature and a second surface having a relatively high temperature is located adjacent to the compartment. A cooling probe is coupled to the first surface, and extends through the compartment wall such that it cools the water in the compartment. The thermoelectric cooling device is commercially available, and produces a temperature differential upon application of a direct voltage due to the Peltier effect.
However, water coolers such as disclosed in the Moren patent can be troublesome due to the fact that the entire volume of liquid in the cooling reservoir may freeze completely. Under such "freeze-up" conditions, the liquid can no longer be dispensed and the cooler is rendered inoperable. Various arrangement of fans, timers, temperature controls, and feed back loops have been utilized in attempts to address the freeze-up problem. However, these measures are complicated to implement and utilize, and largely unreliable in preventing freeze-up. Accordingly, there is a need for a liquid cooler and dispenser which can effectively cool and dispense water, and that can remain operable during freeze-up of the cooling reservoir.